﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;

namespace KingSite.Library.Security {
    public class MD5Entry {
        // Hash an input string and return the hash as
        // a 32 character hexadecimal string.
        public static string GetMd5Hash(string input) {
            // Create a new instance of the MD5CryptoServiceProvider object.
            MD5 md5Hasher = MD5.Create();        // Convert the input string to a byte array and compute the hash.
            byte[] data = md5Hasher.ComputeHash(Encoding.Default.GetBytes(input));        // Create a new Stringbuilder to collect the bytes
            // and create a string.
            StringBuilder sBuilder = new StringBuilder();        // Loop through each byte of the hashed data
            // and format each one as a hexadecimal string.
            for (int i = 0; i < data.Length; i++) {
                sBuilder.Append(data[i].ToString("x2"));
            }        // Return the hexadecimal string.
            return sBuilder.ToString();
        }

        public static string GetMd5Hash(string input, Encoding encoding )
        {
            // Create a new instance of the MD5CryptoServiceProvider object.
            MD5 md5Hasher = MD5.Create();        // Convert the input string to a byte array and compute the hash.
            byte[] data = md5Hasher.ComputeHash(encoding.GetBytes(input));        // Create a new Stringbuilder to collect the bytes
            // and create a string.
            StringBuilder sBuilder = new StringBuilder();        // Loop through each byte of the hashed data
            // and format each one as a hexadecimal string.
            for (int i = 0; i < data.Length; i++)
            {
                sBuilder.Append(data[i].ToString("x2"));
            }        // Return the hexadecimal string.
            return sBuilder.ToString();
        }
        
        // Verify a hash against a string.
        public static bool VerifyMd5Hash(string input, string hash) {
            // Hash the input.
            string hashOfInput = GetMd5Hash(input);        // Create a StringComparer an comare the hashes.
            StringComparer comparer = StringComparer.OrdinalIgnoreCase; if (0 == comparer.Compare(hashOfInput, hash)) {
                return true;
            }
            else {
                return false;
            }
        }

        public static bool VerifyMd5Hash(string input, string hash, Encoding encoding)
        {
            // Hash the input.
            string hashOfInput = GetMd5Hash(input, encoding);        // Create a StringComparer an comare the hashes.
            StringComparer comparer = StringComparer.OrdinalIgnoreCase; if (0 == comparer.Compare(hashOfInput, hash))
            {
                return true;
            }
            else
            {
                return false;
            }
        }
    }
}
